Alfred Russel Wallace quotes:

In all works on Natural History, we constantly find details of the marvellous adaptation of animals to their food, their habits, and the localities in which they are found.

If this is not done, future ages will certainly look back upon us as a people so immersed in the pursuit of wealth as to be blind to higher considerations.

Modification of form is admitted to be a matter of time.

It has been generally the custom of writers on natural history to take the habits and instincts of animals as the fixed point, and to consider their structure and organization as specially adapted to be in accordance with them.

But naturalists are now beginning to look beyond this, and to see that there must be some other principle regulating the infinitely varied forms of animal life.

Civilisation has ever accompanied emigration and conquest - the conflict of opinion, of religion, or of race

I hold with Henry George, that at the back of every great social evil will be found a great political wrong.

I hold with Henry George, that at the back of every great social evil will be found a great political wrong

Modification of form is admitted to be a matter of time

The foregoing considerations lead us to the very important conclusion, that matter is essentially force, and nothing but force; that matter, as popularly understood, does not exist, and is, in fact, philosophically inconceivable.

There is, I conceive, no contradiction in believing that mind is at once the cause of matter and of the development of individualised human minds through the agency of matter.

On the spiritual theory, man consists essentially of a spiritual nature or mind intimately associated with a spiritual body or soul, both of which are developed in and by means of a material organism.

To say that mind is a product or function of protoplasm, or of its molecular changes, is to use words to which we can attach no clear conception.

What we need are not prohibitory marriage laws, but a reformed society, an educated public opinion which will teach individual duty in these matters.

I spent, as you know, a year and a half in a clergyman's family and heard almost every Tuesday the very best, most earnest and most impressive preacher it has ever been my fortune to meet with, but it produced no effect whatever on my mind.

I am decidedly of the opinion that in very many instances we can trace such a necessary connexion, especially among birds, and often with more complete success than in the case which I have here attempted to explain.

Civilisation has ever accompanied emigration and conquest - the conflict of opinion, of religion, or of race.

Truth is born into this world only with pangs and tribulations, and every fresh truth is received unwillingly.

There is, I conceive, no contradiction in believing that mind is at once the cause of matter and of the development of individualised human minds through the agency of matter

As well might it be said that, because we are ignorant of the laws by which metals are produced and trees developed, we cannot know anything of the origin of steamships and railways.

I am thankful I can see much to admire in all religions.

On the spiritual theory, man consists essentially of a spiritual nature or mind intimately associated with a spiritual body or soul, both of which are developed in and by means of a material organism

In my solitude I have pondered much on the incomprehensible subjects of space, eternity, life and death.

What birds can have their bills more peculiarly formed than the ibis, the spoonbill, and the heron?

In less than eight years "The Origin of Species" has produced conviction in the minds of a majority of the most eminent living men of science. New facts, new problems, new difficulties as they arise are accepted, solved, or removed by this theory; and its principles are illustrated by the progress and conclusions of every well established branch of human knowledge.

I have since wandered among men of many races and many religions.

To expect the world to receive a new truth, or even an old truth, without challenging it, is to look for one of those miracles which do not occur.

The white men in our colonies are too frequently the savages

I think I have fairly heard and fairly weighed the evidence on both sides, and I remain an utter disbeliever in almost all that you consider the most sacred truths [...] I can see much to admire in all religions [...] But whether there be a God and whatever be His nature; whether we have an immortal soul or not, or whatever may be our state after death, I can have no fear of having to suffer for the study of nature and the search for truth.

To say that mind is a product or function of protoplasm, or of its molecular changes, is to use words to which we can attach no clear conception

Why do some die and some live? The answer was clearly, that on the whole the best fitted live. From the effects of disease the most healthy escaped; from enemies, the strongest, swiftest, or the most cunning; from famine, the best hunters or those with the best digestion; and so on. Then it suddenly flashed upon me that this self-acting process would necessarily improve the race, because in every generation the inferior would inevitably be killed off and the superior would remain-that is, the fittest would survive.

Mars, therefore, is not only uninhabited by intelligent beings such as Mr. Lowell postulates, but is absolutely uninhabitable.

There might have been a hundred or a thousand life-bearing planets, had the course of evolution of the universe been a little different, or there might have been none at all. They would probably add, that, as life and man have been produced, that shows that their production was possible; and therefore, if not now then at some other time, if not here then in some other planet of some other sun, we should be sure to have come into existence; or if not precisely the same as we are, then something a little better or a little worse.

There is a tendency in nature to the continued progression of certain classes of varieties further and further from the original type.

Truth is born into this world only with pangs and tribulations, and every fresh truth is received unwillingly. To expect the world to receive a new truth, or even an old truth, without challenging it, is to look for one of those miracles which do not occur.

As well might it be said that, because we are ignorant of the laws by which metals are produced and trees developed, we cannot know anything of the origin of steamships and railways

In one of my latest conversations with Darwin he expressed himself very gloomily on the future of humanity, on the ground that in our modern civilization natural selection had no play, and the fittest did not survive. Those who succeed in the race for wealth are by no means the best or the most intelligent, and it is notorious that our population is more largely renewed in each generation from the lower than from the middle and upper classes.

To the mass of mankind religion of some kind is a necessity

Every species has come into existence coincident both in space and time with a pre-existing closely allied species.

What we need are not prohibitory marriage laws, but a reformed society, an educated public opinion which will teach individual duty in these matters